1. Technical Field
The present invention generally relates to frame assemblies for automotive vehicles and, more particularly, to a structural tube for the front end assembly of a motor vehicle unibody.
2. Discussion
A front end assembly of a motor vehicle includes various components for supporting the vehicle's engine, front body panels, and front suspension. In a unibody construction, such a front end assembly commonly includes a pair of rails extending along the longitudinal axis of the vehicle, a bumper beam extending between the pair of rails, a pair of wheel wells disposed outboard of the rails and rearward of the bumper, a fascia coupled between the rearward ends of the wheel wells opposite the bumper beam, and a pair of cowls extending between the bumper beam and fascia outboard of the wheel wells. In order to provide a base for mounting the coolant pack of the vehicle (e.g., the radiator) a support member is sometimes provided behind the bumper beam and between the cowls.
According to the prior art, such a support member is bolted to the rails and cowls. While bolting the support member to the other components of the front assembly is satisfactory for providing a platform for mounting the coolant pack, such bolting is susceptible to torsional failure. That is, since bolting provides a point contact between the support member and the rails and/or cowls, the support member does not add substantially to the cross-car stiffness of the front assembly. Under extreme conditions, cross-car torsion may cause the point contacts to break.
Bolting also requires numerous parts and manual labor during assembly which adds to manufacturing costs. Additionally, bolting is not conducive to high speed automated processing. Further, bolting does not enable small positional adjustments among the components to account for local build variations.
In view of the foregoing, it would be desirable to provide a support member which yields additional cross-car rigidity and stiffness. It would also be desirable to employ an improved connection between the support member and the other components of the front assembly. Additionally, it would be desirable to provide a support member capable of high speed, automated processing.